FDA to Probe Testosterone Therapy Claims, Safety
Joint committee to consider whether 'Low T' products are overprescribed and whether treatment raises heart risks
TUESDAY, Sept. 16, 2014 (HealthDay News) -- The U.S. Food and Drug Administration is focusing on the "Low T" fad, questioning whether the boom in testosterone replacement therapy is helping or harming the health of aging American males.
At a joint meeting scheduled for Wednesday and Thursday, two key FDA committees will discuss whether doctors are prescribing testosterone therapy for too many men, and if misuse of the male hormone increases the risk of stroke and heart attack.
The Baby Boom generation has turned to testosterone replacement therapy in response to the sagging muscles, lower energy levels and sexual problems that can accompany natural aging, the FDA noted in a review provided to committee members in advance of the meeting.
"There's a large group of men out there who are getting older, and they are looking for ways to evade the consequences of aging," said Dr. Bradley Anawalt, an endocrinologist from the University of Washington in Seattle.
However, the FDA review pointed out there's no clear scientific evidence showing testosterone replacement can reverse some of the effects of aging. Yet the "Low T" craze has been aided by consumer advertising for remedies that promise renewed vitality and strength for aging men, the report said. It also noted that there's growing evidence many men who are receiving testosterone replacement therapy do not need it.
At the joint FDA committee meeting in Hyattsville, Md., the panelists will be asked to vote on two key issues: Whether the agency should revise current indication for testosterone therapies, and whether sponsors of testosterone products should conduct studies to further assess a potential cardiovascular risk.
Anawalt said he hopes the FDA hearing will signal increased government oversight of testosterone therapy and increased public funding for studies on its effectiveness.
"This is a hormone that has been used as a therapy for decades without much scrutiny," he added.
The number of patients with a testosterone prescription nearly doubled over three years, leaping from 1.3 million people in 2010 to 2.3 million in 2013, according to the FDA review, done by Dr. Christine Nguyen, the agency's deputy director for safety, and Dr. Hylton Joffee, director of the FDA's division of bone, reproductive and urologic products.
An FDA analysis found that only about one-half of men now taking testosterone therapy have been diagnosed with hypogonadism, the specific medical diagnosis for testosterone deficiency.
Further, 25 percent of men started the therapy without lab testing to confirm that they had low levels of testosterone, the report said. More than one in four never received a lab test during the course of their therapy, which is crucial to making sure the patient's hormone levels are within the normal range, according to the FDA.
"Many endocrinologists feel that testosterone is being prescribed for men without a clear indication for its use, or for men who are not indicated for it at all," said Anawalt.
Testosterone therapy, even if used correctly, could have serious consequences for heart health, the FDA report added.
One recent study found a 30 percent increased risk of stroke or heart attack in a group of men recently prescribed testosterone therapy, the FDA said. Another found that men 65 and older experienced a two-fold increase in heart attack risk within the first three months of receiving a testosterone prescription, according to the agency.
In June, the FDA announced that testosterone supplement products must now carry a warning label on the general risk of blood clots in the veins.
Until a decade ago, testosterone deficiency tended to be a little recognized and undertreated illness, said Dr. Ronald Tamler, director of the Mount Sinai Diabetes Center in New York City.
"Then all of a sudden, the [pharmaceutical] industry started picking up on this and realized that testosterone was a fantastic business, and realized some patients had needed this medication for decades," Tamler said.
Unfortunately, he added, doctors who aren't hormone experts are performing testosterone level tests at the wrong time of the day, which can lead to overdiagnosis of low T.
Testosterone levels are at their peak early in the morning and decline naturally throughout the day. Because of this, endocrinologists know to perform testosterone tests first thing in the morning, Tamler said.
But some doctors have been performing hormone tests at all times of the day, diagnosing some men as having low testosterone when in fact their levels are normal, Tamler said.
"We swiftly went from one extreme to the other extreme, which was overtesting for it, overdiagnosing it and overtreating it," he said.
At the same time, the science is "murky" on the link between testosterone and increased risk of stroke or heart attack, Tamler said. The FDA review agreed, noting that some studies found potential harm, while others found none.
Dr. Daniel Yadegar, a New York City cardiologist who specializes in anti-aging therapies, argues that studies showing a link between testosterone therapy and poor heart health did not consider the role that other hormones might play.
Yadegar noted that a man receiving too much testosterone will begin to convert the hormone into estrogen, which has been shown to increase heart disease risk in men.
"Perhaps it's high estrogen levels that are causing the cardiovascular events, but we would never know that because they didn't measure the estrogen levels," he said.
Yadegar added that the earlier studies relied on blood tests for testosterone, which some research has shown are less accurate than saliva tests for the male hormone.
For more information on the FDA's meetings on testosterone replacement therapy, visit the U.S. Food and Drug Administration (http://www.fda.gov/AdvisoryCommittees/CommitteesMeetingMaterials/Drugs/ReproductiveHealthDrugsAdvisoryCommittee/ucm404895.htm ).
SOURCES: Ronald Tamler, M.D., director, Mount Sinai Diabetes Center, and associate professor of endocrinology, Icahn School of Medicine at Mount Sinai, New York City; Bradley Anawalt, M.D., representative, The Endocrine Society, and endocrinologist, University of Washington, Seattle, Wash.; Daniel Yadegar, M.D., cardiologist, New York City; FDA briefing information for Sept. 17, 2014, Joint Meeting of the Bone, Reproductive and Urologic Drugs Advisory Committee and the Drug Safety and Risk Management Advisory Committee Meeting
12 States Now Reporting Severe Respiratory Illness That Targets Kids
Health officials urge good hygiene to limit exposure to Enterovirus D68
WEDNESDAY, Sept. 17, 2014 (HealthDay News) -- Twelve states now have confirmed cases of Enterovirus D68, the severe respiratory illnesses that may have sickened hundreds of children, U.S. health officials report.
Alabama, Colorado, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Missouri, New York, Oklahoma and Pennsylvania collectively have 130 laboratory-confirmed cases of Enterovirus D68, according to the U.S. Centers for Disease Control and Prevention.
The virus, part of the family of viruses that includes the common cold, can sometimes require hospitalization, especially for children with asthma.
More cases will be confirmed in the coming weeks because the testing for Enterovirus D68 is complex and can only be done by the CDC and a small number of state-run laboratories, the CDC said.
The first cases were diagnosed last month in Midwestern and Western states and have now spread to the Northeast and Louisiana.
Enteroviruses are common in September as kids head back to school, with an estimated 10 million to 15 million people infected each year. But doctors believe this particular type of enterovirus is causing more severe cases than in the past, and can be troublesome for kids with asthma.
The virus is also hard to track because it causes symptoms similar to many other infections, including the common cold, experts have said.
"It is important that we follow common sense rules to prevent the spread of this virus, as we do for flu and other contagious illnesses," New York state acting Health Commissioner Dr. Howard Zucker said in a statement. "Because there is no specific treatment or vaccination against this virus, our best defense is to prevent it by practicing proper hygiene."
Illness associated with the Enterovirus D68 infection typically lasts about a week. Children will appear to have a severe cold, with runny nose, sneezing and cough. But the illness can escalate quickly in some cases, and the child may start to have trouble breathing. It's typically transmitted through close contact with an infected person, or by touching objects or surfaces contaminated with the virus and then touching the mouth, nose or eyes, according to health officials.
Antibiotics won't work against a virus, and there is no antiviral treatment available for Enterovirus D68, public health officials said.
The CDC is asking doctors and public health officials to consider Enterovirus D68 as a potential suspect if widespread respiratory illnesses start occurring in their communities.
Dr. Len Horovitz, a pulmonary specialist at Lenox Hill Hospital in New York City, agreed that good hygiene is the best defense against a child catching Enterovirus D68.
"Hand washing is paramount, and teaching kids not to touch their faces with unwashed hands is the point," Horovitz said. "Any child or adult with flu-like symptoms or common cold symptoms should be seen, evaluated and followed by doctors for any respiratory complications."
Children and adults should wash their hands with soap and water for at least 20 seconds on a regular basis. They also should avoid contact with people who are sick, and stay home if they themselves fall ill. Kids with asthma need to stay on top of their symptoms and take their medication, public health officials said.
The virus tends to "produce severe shortness of breath in children who may not have asthma. Therefore, children with asthma must be watched closely by doctors if they contract the virus," Horovitz said.
Enteroviruses are very common, according to the CDC. There are more than 100 types of enteroviruses. People who come down with a bad summer cold often have been laid low by an enterovirus, the federal agency said.
To learn more about enteroviruses, visit the U.S. Centers for Disease Control and Prevention (http://www.cdc.gov/non-polio-enterovirus/ ).
SOURCES: U.S. Centers for Disease Control and Prevention; Len Horovitz, M.D., pulmonary specialist, Lenox Hill Hospital, New York City
'Biospleen' Suggests New Way to Treat Blood Infection
But more research needed before blood-cleansing device is used on humans to treat sepsis
WEDNESDAY, Sept. 17, 2014 (HealthDay News) -- Scientists have developed a blood-cleansing device, called the "biospleen," that they say could potentially change the way the blood infection sepsis is treated.
Researchers at Harvard's Wyss Institute for Biologically Inspired Engineering said their device works outside the body like a dialysis machine, and can quickly filter bacteria, fungi and toxins out of patients' blood.
"Even with the best current treatments, sepsis patients are dying in intensive care units at least 30 percent of the time," Mike Super, a senior staff scientist at the Wyss Institute, said in an institute news release. "We need a new approach."
Sepsis, a life-threatening condition in which bacteria or fungi multiply in the blood, claims at least 8 million lives around the world each year. It's also the leading cause of hospital deaths.
Sepsis is currently treated with antibiotics, but it often progresses too quickly for this approach to work. The increasing prevalence of drug-resistant bacteria makes treating sepsis more difficult.
The researchers modeled their design after the human spleen, which removes pathogens (germs) and dead cells from the blood through a series of tiny interwoven blood channels.
The biospleen they created consists of two adjoining hollow channels connected by a series of slits. While one channel contains flowing blood, the other has a saline solution that removes the germs that pass through the slits.
The biospleen was first tested with infected human blood in a lab before being tested on rats. In just hours the biospleen filtered live and dead germs and the deadly toxins they release, the researchers reported Sept. 14 in Nature Medicine. The device also increased the survival of the rats with sepsis, the researchers said.
The human blood was filtered at a rate of about half a liter to one liter per hour, the study authors noted in the news release.
The rats involved in the study were infected with E. coli and other bacteria and toxins that are similar to human bloodstream infections. The researchers found that roughly 90 percent of the bacteria and toxins were removed from the rats' blood after five hours of filtering. While 90 percent of the treated rats survived, 14 percent of those in an untreated "control" group did not.
"We didn't have to kill the pathogens. We just captured and removed them," Super said in the news release.
Dr. Don Ingber, founding director of the Wyss Institute, said sepsis is a major medical threat, which is increasing because of antibiotic resistance. "We're excited by the biospleen because it potentially provides a way to treat patients quickly without having to wait days to identify the source of infection, and it works equally well with antibiotic-resistant organisms," Ingber said.
"We hope to move this towards human testing to advancing to large animal studies as quickly as possible," he added.
The U.S. Centers for Disease Control and Prevention has more about sepsis (http://www.cdc.gov/sepsis/ ).
SOURCE: Wyss Institute for Biologically Inspired Engineering at Harvard, news release, Sept. 14, 2014
DNA Blood Test Might Identify Status of Prostate Cancer
May help doctors pinpoint best treatment, researchers say
WEDNESDAY, Sept. 17, 2014 (HealthDay News) -- A blood test that measures DNA from a prostate cancer tumor could provide doctors with a better assessment of the state of a man's disease, a new study suggests.
If used routinely, this blood test could reveal when treatment for advanced prostate cancer stops working and actually begins promoting tumor growth, the researchers suggested.
"Our study showed that a steroid treatment given to patients with advanced prostate cancer and often initially very effective started to activate harmful mutations and coincided with the cancer starting to grow again," study leader Dr. Gerhardt Attard, from the Institute of Cancer Research (ICR) in London, explained in an ICR news release.
"In the future, we hope to routinely monitor genetic mutations in patients with advanced disease using just a blood test -- enabling us to stop treatments when they become disease drivers and select the next best treatment option. We need to confirm these findings in larger numbers of patients, but using these types of blood tests could allow true personalization of treatment for prostate cancer patients, based on the cancer mutations we detect," he explained.
Using a blood test to measure circulating tumor DNA levels is less expensive and less invasive than needle biopsies. This test could be an effective way to monitor the emergence of treatment-resistant prostate cancer, the study published on Sept. 17 in Science Translational Medicine suggested.
"Drug resistance is the single biggest challenge we face in cancer research and treatment, and we are just beginning to understand how its development is driven by evolutionary pressures on tumors," Paul Workman, interim chief executive at the ICR, said in the news release.
This discovery "reveals how some cancer treatments can actually favor the survival of the nastiest cancer cells, and sets out the rationale for repeated monitoring of patients using blood tests, in order to track and intervene in the evolution of their cancers," Workman said.
"There are currently too few treatment options for men living with advanced stage prostate cancer. Not only do we desperately need to find more treatments for this group of men, we also need to understand more about when those that are available stop working and why," Dr. Matthew Hobbs, deputy director of research at Prostate Cancer UK, said in the news release.
"This research is important as it shows that there might be a new way to monitor how a man's cancer is changing during treatment, and that could help us to pinpoint the stage at which some drugs stop being effective. In the future, this could arm doctors with the knowledge they need to ensure that no time is wasted between a drug that stops working for a man and him moving on to another effective treatment," Hobbs said.
But, Hobbs also noted that this is preliminary research and that the study size was small -- just 16 men. He agreed with Attard that the findings need to be confirmed in a larger study.
The researchers cautioned that any patients currently taking medication for advanced prostate cancer should continue to take their medications as prescribed and discuss any concerns about their treatment with their doctor.
The U.S. National Cancer Institute provides more information on prostate cancer (http://www.cancer.gov/cancertopics/types/prostate ).
SOURCE: Institute of Cancer Research, news release, September 17, 2014
Modern Forensics Provides Clues to Death of Richard III
Analysis of skeletal remains sheds light on fatal injuries English king suffered in battle over 500 years ago
TUESDAY, Sept. 16, 2014 (HealthDay News) -- Modern forensic techniques are shedding light on a 500-year-old mystery: Which battlefield injuries might have killed King Richard III, the last English monarch to die in battle?
A new analysis of the king's skeletal remains, using whole-body CT scans and micro-CT imaging of injured bones, provides a detailed account of the 11 injuries he suffered at the Battle of Bosworth Field, where he died on Aug. 22, 1485.
The modern forensics revealed that two skull injuries could have killed the king in a short amount of time, according to a new report published Sept. 16 in The Lancet.
The skeletal remains of the king were discovered under a Leicester parking lot in 2012 by archaeologists from the University of Leicester. Since then, the university's forensic imaging team, in collaboration with the forensic pathology unit and department of engineering, has analyzed his wounds. They also examined tool marks on his bones to identify the medieval weapons that may have caused his injuries.
The team, led by Dr. Jo Appleby of the university's School of Archaeology and Ancient History, was able to determine which of the king's wounds might have been fatal.
The study showed of the 11 injuries he sustained at or near the time of his death, nine were wounds to his skull. The researchers noted this head trauma occurred during battle, suggesting Richard either removed or lost his helmet.
"Richard's injuries represent a sustained attack or an attack by several assailants with weapons from the later medieval period," study author Sarah Hainsworth, a professor of materials engineering at the university, said in a journal news release. "The wounds to the skull suggest that he was not wearing a helmet, and the absence of defensive wounds on his arms and hands indicate that he was otherwise still armored at the time of his death."
The researchers concluded that some of the king's injuries, including a wound to his pelvis, may have been inflicted after his death. If he were alive, they explained, he would have been wearing a specific type of armor that would have protected him from such wounds.
"The most likely injuries to have caused the King's death are the two to the inferior aspect of the skull -- a large sharp force trauma possibly from a sword or staff weapon, such as a halberd or bill, and a penetrating injury from the tip of an edged weapon," study co-author Guy Rutty, from the East Midlands Pathology Unit at the university, said in the news release.
The study itself noted, "If inflicted in life, either of the injuries on the inferior aspect of the cranium could result in subarachnoid hemorrhage, injury to the brain, or an air embolus. Any . . . would be potentially fatal within a short time. The injuries are highly consistent with the body having been in a prone position or on its knees with the head pointing downwards."
Rutty added, "Richard's head injuries are consistent with some near-contemporary accounts of the battle, which suggest that Richard abandoned his horse after it became stuck in a mire and was killed while fighting his enemies."
In the study, the researchers added this end-note: "The fact that the face is not more completely destroyed might relate to the need to display Richard's corpse after the battle, which was done to reduce the chances of future pretenders claiming the throne in Richard's name."
The U.S. National Library of Medicine has more about modern forensic science (http://www.nlm.nih.gov/visibleproofs/exhibition/newscience.html ).
SOURCE: The Lancet, news release, Sept. 16, 2014
Researchers Discover How Bacteria Resist Antibiotics in Hospitals
Spotting infected patients, disinfecting hospitals key to curbing spread of resistant bacteria, experts say
WEDNESDAY, Sept. 17, 2014 (HealthDay News) -- Scientists have uncovered a key factor to explain why antibiotic-resistant bacteria can thrive in a hospital setting.
Tiny circles of DNA called plasmids appear to be the culprit. They can easily enter bacteria and move from one bacteria to another, and some carry a gene that makes bacteria drug-resistant, a new study finds.
"The plasmids we are talking about carry an antibiotic-resistant gene to a class of antibiotic called carbapenems," said the study's co-author, Dr. Tara Palmore, an infection control specialist at the U.S. National Institutes of Health.
Carbapenems are antibiotics of last resort, and carbapenem-resistant Enterobacteriaceae (CRE) are bacterial pathogens that pose a "formidable" threat to hospitalized patients, according to the research.
The incidence of CRE has quadrupled in the last decade in the United States, according to background information in the report. CRE has been detected in nearly 4 percent of hospitals and about 18 percent of long-term acute care facilities. In addition, the researchers noted, CRE are resistant to most, if not all, antibiotics. Investigations have reported a death rate of 40 percent to 80 percent from infection.
Given ongoing concerns that even bacteria like Klebsiella and Enterobacter -- which are found in the environment and in healthy stomachs -- are becoming increasingly resistant to last-resort antibiotics, the researchers set out to find some answers. Their report, published Sept. 17 in Science Translational Medicine, showed that plasmid transfer in hospitals is likely contributing to the increase in antibiotic-resistant bacteria.
Using advanced DNA sequencing of samples from more than 1,000 patients, the researchers were able to see the complete genome of bacteria samples and identify the antibiotic-resistant genes -- plasmids -- located in those samples.
Plasmids can multiply independently and integrate their DNA with the DNA of the bacteria. And plasmids that have the gene that inactivates certain antibiotics can be transferred to bacteria of various types, the scientists found.
Over the course of two years, the researchers identified 10 patients seen at the U.S. National Institutes of Health Clinical Center who had resistance to carbapenems.
The investigators also found antibiotic-resistant genes in tiny collections of organisms called biofilms living in hospital sink drains in patient rooms.
This finding did not show that bacteria from the sink drain were passed to any patient, the study authors said.
But even though patients who carry this bacteria may not be sick themselves, they can pass this drug-resistant bacteria to others, they added.
Study co-author Julie Segre, chief and senior investigator at the U.S. National Human Genome Research Institute, noted, "We are trying to reinforce the message that these drug-resistant bacteria can't become so prevalent that we can no longer control them."
And she emphasized, "We are still at the point where we can make a difference in terms of controlling the bacteria."
However, Palmore said, knowing how bacteria become drug-resistant doesn't change how preventing its spread is carried out.
"It informs us of how bacteria can pick up the resistance," Palmore said. "Efforts to control these bacteria need to focus on containing them by isolating patients who are carriers of the bacteria and also by disinfecting the hospital environment where the bacteria might live."
Victoria Richards, an associate professor of medical sciences at the Frank H. Netter MD School of Medicine at Quinnipiac University in North Haven, Conn., was not involved with the study but was familiar with the findings. She said, "Bacteria don't want to be killed. When we try to kill them with antibiotics, they are going to fight back. It's an ongoing battle."
Dr. Marc Siegel, an associate professor of medicine at NYU Langone Medical Center in New York City, another expert who was not involved in the study, said, "Carbapenems are the best we have. So if you've got carbapenem-resistance, there is nowhere else for us to go. We don't have a secret treatment up our sleeves."
Siegel thinks that drug companies need to create new antibiotics, which doctors would then need to use more cautiously. In addition, he added, hospitals need to be doing a better job with disinfectants.
For more on antibiotic resistance, visit the U.S. Centers for Disease Control and Prevention (http://www.cdc.gov/drugresistance/ ).
SOURCES: Tara Palmore, M.D., infection control specialist, U.S. National Institutes of Health; Julie Segre, Ph.D., chief, and senior investigator, U.S. National Human Genome Research Institute; Marc Siegel, M.D., associate professor, medicine, NYU Langone Medical Center, New York City; Victoria Richards, Ph.D., associate professor, medical sciences, Frank H. Netter MD School of Medicine, Quinnipiac University, North Haven, Conn.; Sept. 17, 2014, Science Translational Medicine
Are Migraines in Middle Age Tied to Raised Parkinson's Risk Later?
Study sees a connection, but actual risk is small; more study needed, researchers say
WEDNESDAY, Sept. 17, 2014 (HealthDay News) -- Migraines in midlife may be associated with increased odds of developing Parkinson's disease or other movement disorders in later years, new research suggests.
The study, which did not prove a cause-and-effect link between the two brain-based conditions, also suggested that the migraine-Parkinson's association was stronger in women with migraines preceded by aura. An aura is a warning sign of a pending attack that includes flashes of light and skin tingling.
"We should emphasize that while the risk is increased for Parkinson's disease and these [similar] symptoms, they're still uncommon among those with migraine," said study author Ann Scher, a professor of epidemiology at Uniformed Services University in Bethesda, Md. "I don't think people should necessarily worry that if they have migraines, Parkinson's disease is [in their future]."
The research is published in the Sept. 17 online edition of the journal Neurology.
Throbbing, chronic headaches that impact about 28 million Americans aged 12 and up, migraines affect three times as many women as men, according to the American Headache Society.
Meanwhile, about 1 million people in the United States have Parkinson's disease and up to 60,000 more are diagnosed each year, according to the National Parkinson Foundation. The incurable neurological condition causes tremors, stiffness, slow movement, and impaired balance and coordination.
Scher and her colleagues reviewed records of more than 5,600 Icelandic people aged 33 to 65 who were tracked for 25 years. At the study's start, about 4,000 participants had no headaches, with 1,028 suffering non-migraine headaches, 238 migraine with no aura and 430 migraine with aura.
In later life, participants were asked whether they'd been diagnosed with Parkinson's or experienced symptoms; had a family history of Parkinson's; or had symptoms of restless legs syndrome, a movement disorder characterized by uncomfortable leg sensations and an irresistible urge to move the legs.
The findings showed that those with migraine with aura at midlife were more than twice as likely to have been later diagnosed with Parkinson's than people with no headaches. Those with migraine with aura were 3.6 times as likely to report four of six parkinsonian symptoms, while those with migraine with no aura were 2.3 times more likely. Overall, the study found nearly 20 percent of those with migraine with aura had symptoms, compared to 12.6 percent of those with migraine with no aura and 7.5 percent of those with no headaches.
Both Parkinson's disease and restless legs syndrome involve a dysfunction in the brain chemical dopamine, Scher said, and migraine development is also thought to be associated with dopamine abnormalities. Future research should examine whether Parkinson's and migraine share genetic risk factors, she added.
"Previous studies noted that migraine, particularly migraine with aura, was linked to cardiovascular disease and stroke, so there's increasing interest in whether these linkages might manifest in other neurological symptoms later in life," Scher said.
Dr. Michael Okun, national medical director of the National Parkinson Foundation, called the new research "interesting." But he said it had several notable weaknesses, including that its participants were only from the Icelandic region and that some patients reporting Parkinson's symptoms had not been formally diagnosed with the disorder.
"The idea that a history of migraine headaches has something to do with Parkinson's is intriguing, but there's not a lot of scientific data right now that would support that notion," said Okun, also co-director of the Movement Disorders Center at the University of Florida. "I'd be extremely cautious to conclude that migraine is associated with Parkinson's."
The U.S. National Library of Medicine has more about Parkinson's disease (http://www.nlm.nih.gov/medlineplus/parkinsonsdisease.html ).
SOURCES: Ann Scher, Ph.D., professor, epidemiology, Uniformed Services University, Bethesda, Md.; Michael Okun, M.D., national medical director, National Parkinson Foundation, and co-director, Movement Disorders Center, University of Florida, Gainesville, Fla.; Sept. 17, 2014, Neurology, online
Artificial Sweeteners May Raise Blood Sugar Levels: Study
Scientists saw changes in helpful gut bacteria, which can affect some people's ability to process glucose
WEDNESDAY, Sept. 17, 2014 (HealthDay News) -- Diabetics and dieters who turn to artificial sweeteners to soothe their sweet tooth may not be doing themselves any favors, a new Israeli study suggests.
Artificial sweeteners can potentially make blood sugar levels rise despite containing no calories, researchers found in human and mouse studies.
That's because saccharine and its counterparts appear to alter the bacteria residing in the intestines in ways that can impair some people's ability to process glucose, the researchers report in the Sept. 17 issue of Nature. That means rather than helping the current epidemics of obesity and type 2 diabetes in the United States, artificial sweeteners could potentially be contributing to the problem, according to the study.
The researchers found that mice fed artificial sweeteners developed higher blood sugar levels compared to mice drinking plain water or even water laced with sugar.
They further found that they could bring the mice's blood sugar levels back to normal by treating them with antibiotics. And, they could induce higher blood sugar levels in healthy mice never exposed to artificial sweeteners by transplanting gut bacteria from mice who had been fed saccharine.
Turning to a group of nearly 400 people, the researchers found that long-term users of artificial sweeteners were more likely to have higher fasting blood sugar levels. They were also more likely to have signs of impaired glucose processing, compared with people who don't normally use such sweeteners.
In a small follow-up experiment, the researchers tested blood sugar levels of seven people who don't normally consume artificial sweeteners. The researchers found that four of these people had higher blood sugar levels after consuming the U.S Food and Drug Administration's maximum recommended daily amount of saccharine for six days straight.
"We were surprised, given the massive consumption and use of artificial sweeteners and their general regard as being safe," said the study's co-author Eran Segal, a professor of computer science and applied mathematics at the Weizmann Institute of Science in Rehovot, Israel.
Even though the human and mouse studies mainly focused on saccharine, the first set of mouse experiments also included sucralose and aspartame, Segal said. All three appeared to have the same effect on blood sugar levels in mice.
The researchers said that no one should make immediate dietary choices based on these findings.
"We must stress that by no means are we saying sugary drinks are healthy and should be brought back as a healthy part of our nutrition," said lead author Dr. Eran Elinav of the Weizmann Institute's Immunology Department.
But the team found evidence that some people may be more susceptible than others to blood sugar increases caused by artificial sweeteners.
By profiling the bacterial content of a person's gut, "we could cluster them in a way that would show who would respond and not respond to artificial sweeteners," Segal said.
Elinav believes that in the guts of those people who developed elevated blood sugar, certain bacteria reacted to the chemical sweeteners by secreting substances that then provoked an inflammatory response similar to sugar overdose, promoting changes in the body's ability to utilize sugar.
These findings bolster the American Diabetes Association's position that "using non-nutritive sweeteners is not a panacea," said Judy Wylie-Rosette, an ADA spokesperson and professor of epidemiology at the Albert Einstein College of Medicine in New York City.
"If you don't have a carefully planned approach to your diet, artificial sweeteners are not going to provide you much benefit," Wylie-Rosette said. "If you're thinking about what you're eating, it may help some."
However, artificially sweetened sodas are clearly better than sugary sodas, Wylie-Rosette added, noting that a person drinking a single 20-ounce regular soda is getting close to 20 extra teaspoons of sugar in their daily diet.
"Water is the best alternative, and non-nutritive sweeteners are somewhere in between," she said. "When you're thirsty, you need to drink water. Water is the best thirst-quenching beverage."
For more information on artificial sweeteners, visit the Harvard School of Public Health (http://www.hsph.harvard.edu/nutritionsource/healthy-drinks/artificial-sweeteners/ ).
SOURCES: Eran Segal, Ph.D., professor of computer science and applied mathematics, Weizmann Institute of Science, Rehovot, Israel; Eran Elinav, M.D., immunology department, Weizmann Institute of Science, Rehovot, Israel; Judy Wylie-Rosette, Ed.D., spokesperson, American Diabetes Association, and professor of epidemiology, Albert Einstein College of Medicine, New York City; Sept. 17, 2014, Nature
Europeans Are Descendants of at Least 3 Ancient Human Groups: Study
New genetic analysis reveals DNA from North Eurasians, researchers say
WEDNESDAY, Sept. 17, 2014 (HealthDay News) -- Present-day Europeans are the descendants of at least three groups of ancient humans, according to a new study.
Previous research suggested that Europeans descended from indigenous hunter-gatherers and early European farmers. But, a new genetic analysis involving ancient bone samples revealed they are also the descendants of Ancient North Eurasians. Nearly all present-day Europeans have genetic material from this third ancestral group, researchers from Harvard Medical School said.
In conducting its investigation into Europeans' heritage, the team of researchers collected and sequenced the DNA of more than 2,300 people currently living around the world. They also examined DNA from nine ancient humans from Germany, Luxembourg and Sweden.
The ancient samples were taken from the bones of eight hunter-gatherers who lived about 8,000 years ago, and one farmer who lived about 7,000 years ago.
"Ancient DNA has emerged as a powerful technology that makes it possible to go back in time to understand how people in the past relate to people today," study co-senior author, David Reich, professor of genetics at Harvard Medical School, said in a university news release.
About 7,500 years ago in Europe, agriculture from the Near East brought early farmers into contact with hunter-gatherers who had been living in Europe for tens of thousands of years. Nearly all Europeans are the result of the mixing of these two ancient populations.
"There was a sharp genetic transition between the hunter-gatherers and the farmers, reflecting a major movement of new people into Europe from the Near East," noted Reich.
The study's authors found, however, Ancient North Eurasians also contributed DNA to present-day Europeans. Ancient North Eurasians also likely contributed DNA to people who crossed the Bering Strait into the Americas more than 15,000 years ago, according to the researchers.
"Nearly all Europeans have ancestry from all three ancestral groups," explained the study's first author, Iosif Lazaridis, a research fellow in genetics in Reich's lab.
"Differences between them are due to the relative proportions of ancestry. Northern Europeans have more hunter-gatherer ancestry -- up to about 50 percent in Lithuanians -- and Southern Europeans have more farmer ancestry," Lazaridis said in the news release.
Before this paper was published, Reich said, "the models we had for European ancestry were two-way mixtures. We show that there are three groups."
Lazaridis pointed out that "the Ancient North Eurasian ancestry is proportionally the smallest component everywhere in Europe, never more than 20 percent, but we find it in nearly every European group we've studied and also in populations from the Caucasus and Near East. A profound transformation must have taken place in West Eurasia" after farming arrived, he added.
The research published online Sept. 17 in Nature found that Ancient North Eurasians also contributed DNA to Native Americans. "This also explains the recently discovered genetic connection between Europeans and Native Americans," Reich said.
Meanwhile, ancient Near Eastern farmers and their European descendants can trace much of their ancestry back even further to an older lineage called the Basal Eurasians, the study authors pointed out in the news release.
"This deep lineage of non-African ancestry branched off before all the other non-Africans branched off from one another," Reich said. "Before Australian Aborigines and New Guineans and South Indians and Native Americans and other indigenous hunter-gatherers split, they split from Basal Eurasians. This reconciled some contradictory pieces of information for us."
Looking ahead, the researchers plan to investigate when the Ancient North Eurasians arrived in Europe. They also want to find ancient DNA from the Basal Eurasians.
"There are important open questions about how the present-day people of the world got to where they are," said Reich. "The traditional way geneticists study this is by analyzing present-day people, but this is very hard because present-day people reflect many layers of mixture and migration."
The U.S. National Library of Medicine has more about genetic ancestry testing (http://ghr.nlm.nih.gov/handbook/testing/ancestrytesting ).
SOURCE: Harvard Medical School, news release, Sept. 17, 2014
Healthy Lifestyle Changes Linked to Reduced Risk for Dementia
Never too late to take steps to help avoid the memory-robbing disorder, researchers say
WEDNESDAY, Sept. 17, 2014 (HealthDay News) -- Managing diabetes, quitting smoking, controlling high blood pressure, exercising and maintaining a healthy weight can reduce the risk for dementia -- even late in life, according to new research.
The World Alzheimer Report 2014, commissioned by Alzheimer's Disease International, revealed that diabetes can increase the risk of dementia by 50 percent. The study noted that obesity and an inactive lifestyle are key risk factors for diabetes as well as high blood pressure.
The researchers suggested that dementia should be included in national public health prevention and detection programs along with other major non-communicable diseases, such as cancer and heart disease. They pointed out that it's never too late in life to make healthy lifestyle changes.
"While age and genetics are part of the disease's risk factors, not smoking, eating more healthily, getting some exercise, and having a good education, coupled with challenging your brain to ensure it is kept active, can all play a part in minimizing your chances of developing dementia," Graham Stokes, global director of dementia care at the international health care group Bupa, said in a news release from King's College London in England.
"People who already have dementia, or signs of it, can also do these things, which may help to slow the progression of the disease," Stokes added.
A team of researchers, led by Martin Prince, a professor at King's College London's Institute of Psychiatry, Psychology and Neuroscience, found that quitting smoking had a strong link with a reduced risk for developing dementia.
The report, published on the Alzheimer's Disease International website in advance of World Alzheimer's Day on Sept. 21, found that among people aged 65 and older, former smokers have a dementia risk that is similar to never-smokers. In contrast, current smokers are at much higher risk for this mental decline.
People with more education are also at lower risk for dementia. Although education doesn't affect the brain changes that lead to dementia, it can reduce their impact on brain function, the researchers explained.
Changes in the brain can begin long before symptoms develop. The investigators concluded that growing older with a stimulated and healthy brain can help people live longer, more independent lives.
Although survey data from Bupa has shown that many people are worried about developing dementia, few know about some specific steps that can help reduce their risk, including being socially active with friends and family, losing weight and exercising.
"There is already evidence from several studies that the incidence of dementia may be falling in high-income countries, linked to improvements in education and cardiovascular health," Prince said in the news release. "We need to do all we can to accentuate these trends. With a global cost of over $600 billion, the stakes could hardly be higher."
And, added Marc Wortmann, executive director of Alzheimer's Disease International, "From a public health perspective, it is important to note that most of the risk factors for dementia overlap with those for the other major non-communicable diseases."
Wortmann explained in the news release that "in high-income countries, there is an increased focus on healthier lifestyles, but this is not always the case with lower- and middle-income countries. By 2050, we estimate that 71 percent of people living with dementia will live in these regions, so implementing effective public health campaigns may help to reduce the global risk."
The U.S. National Library of Medicine has more about dementia (http://www.nlm.nih.gov/medlineplus/dementia.html ).
SOURCE: King's College London, news release, Sept. 16, 2014